Multifunctional materials for photo-electrochemical water splitting

The energy crisis and depletion of non-renewable energy resources have been aggravated due to the drastic rise in world pollution and the energy demand. Facile hydrogen production through water splitting has become a popular alternative source of energy owing to the numerous environmentally friendly and economic benefits it provides. Additionally, it is preferred due to the depletion of non-renewable energy resources, pollution caused by the burning of non-renewable energy resources, and climate change. Hydrogen is generated from water and acts as a clean energy without contributing to carbon emissions. Various water-splitting methods such as electrolysis, thermochemical, mechanocatalysis, plasmolysis, photocatalysis, and photoelectrocatalysis can be applied to obtain hydrogen and oxygen. This review highlights the multifunctional materials used in photo-electrochemical water splitting and their superior properties for producing carbon-free energy from water. Multifunctional materials help reduce aqueous protons to hydrogen and oxidize water to oxygen during the splitting of water. This paper discusses a wide class of materials such as carbon materials, metal-organic frameworks, perovskites, and semiconducting oxides for efficient hydrogen production. Different types of water-splitting methods and multifunctional materials with varying properties can lead to improved results. The review sheds light upon the hydrogen economy and future prospects, elucidating the selection of multifunctional materials for efficient hydrogen production.